The present invention relates to cardiac pacers and particularly involves an hermetically-sealed pacer containing a single rechargeable cell.
Present commercially available non-rechargeable mercury-zinc battery powered implantable cardiac pacemakers have a mean life of approximately 24 months and eventually fail from battery exhaustion or electronic component malfunction usually due to gradual absorption of body fluids through the pacemaker housing. More recently developed longer life units such as rechargeable and nuclear cell models have not as yet been fully proven by long clinical experience and even if functionally successful, could prove to be relatively expensive.
As a result there is a need for a safe, relatively inexpensive pacemaker which is hermetically sealed against moisture intrusion and which is capable of an extended long life. Such a device should also be light in weight, have a shape and surface condition compatible with its biological environment, be immune to radio frequency fields and have components which are readily avaialable and of proven reliability. The presnt invention is intended to fulfill all of these requirements.